Most of the jobs will be in corporate finance, according to spokesman Jason Gowar, and the firm is aiming to offer other jobs to those affected.

Gowar said about half of the partners leaving are being made redundant and the others are due to retire.

The firm is in consultation with employees whose jobs are at risk and the process is expected to be completed before Christmas.

Gowar said the cuts are due to consolidation following the merger with Robson Rhodes a year ago and what he described as "the significant downturn in the market, particularly in corporate finance and related advisory services".

He said: "Next year will be a difficult one financially for everyone, not just for Grant Thornton."

He added that no further cuts are planned but said he does not "have a crystal ball" to predict how the economy will perform over the coming year.

Grant Thornton earned £394m in fee income this year. Its next results are due to be announced this week, but Gowar declined to give any guidance. The cutbacks are among the biggest to be announced by one of Britain's major accountancy firms.

Robert Hannah, who became the head of Grant Thornton in Scotland during the summer, warned this month that it would take a year for the investment market to recover from the downturn and a further two years before the rest of the economy is back on track.

Grant Thornton comes just behind the "big four" accountancy firms, PricewaterhouseCoopers, Deloitte, Ernst & Young and KPMG, in terms of fee income.

The firm has 27 offices in Britain, one in the Cayman Islands and another in the British Virgin Islands.

Scotland will see seven job cuts among 200 working for Grant Thornton. Two of those are as a result of its forensic accountancy department being closed down.

The firm said none of its nine partners in Scotland are at risk.

It added that six out of seven of those employees who have been hit north the border do most of their business outside the country.